In plastic technology molded parts usually are produced in large numbers using an injection molding process and microtechnically fabricated mold inserts, whereupon they are forwarded in bulk for mounting. This process also is used for mounting microstructured molded parts, called microcomponents in the following, whereby the mounting tolerances of the microcomponents are significantly smaller due to the microstructures in comparison to molded parts without microstructures.
A disadvantage of this process is that the specified ordered state is lost during replicative microcomponent production due to the mold insert, so that the molded parts must be mounted individually. Additionally, many devices are necessary to restore the ordered state and to mount the microcomponents.
Prior art exists to avoid these disadvantages by packaging the microcomponents prior to their mounting in a separate and additionally fabricated holder or magazine so many microcomponents can be mounted at once. Major disadvantages of handling the microcomponents this way are that the two separate production process for the microcomponents and the magazine result in manufacturing tolerances that cause inaccuracies in positioning and placing of the microcomponents inside the magazine. Additionally, due to the required separate packaging step joints inside the magazine are needed for storing the microcomponents. Subsequently, this procedure does not significantly reduce costs, in particular equipment costs up to and during mounting of the microcomponents.
To avoid the additional magazine-mounting step, the applicant has filed two procedures already, which disclose a direct consecutive fabrication of microcomponents and storage magazine, eliminating the disadvantages described before.
The prior art in WO 98/39230 describes a procedure to fabricate and package microcomponents and a magazine for at least one microcomponent as well as mounting procedures for microcomponents. In the first step of this procedure, at least one microcomponent is made on top of a component base plate. Then the exposed lateral surfaces of the microcomponent are cast in using a solidifying forming material. Subsequently, the component base plate and/or the mold material covering the microcomponent is removed by a mechanical process like grinding, lapping, milling, or polishing. The resulting magazine for at least one microcomponent consists of a disk-shaped plate that provides a positive enclosure of the microcomponent's lateral surfaces. The mounting procedure provides that the magazine is gripped and held by a magazine holder, whereupon the microcomponent to be mounted is pressed out of the magazine and positioned at its final location.
The prior art in WO 98/39501 describes a procedure to fabricate and package metallic microcomponents. In the first step of this procedure, a magazine is fabricated from electrically non-conductive mold material that positively enclosed the lateral surfaces of at least one microcomponent made of a chemically soluble material (first type microcomponent). The preferred mode of fabrication for the magazine with first type microcomponents uses the above-described procedure of WO 98/39230 for the fabrication and packaging of microcomponents. In a second step of the procedure, a coating or substrate consisting of an electrically conductive material is applied to one side of the magazine and its first type microcomponent. In the next step, the first type microcomponent is removed. Then the empty magazine is filled with a metal or a metal alloy for the fabrication of a second type microcomponent. Finally, the coating or substrate is removed.
The disadvantage of both described procedures is that the microcomponents first have to be replicated on a base plate and then the mold material has to be poured into a mold to fixate the microcomponent in its position. This requires an extensive additional process step for the magazine fabrication, and the base plate as well as the excess mold material above the microcomponent in the mold must be removed by a mechanical process. Since the magazine provides a positive enclosure of the microcomponent sides, the magazine height always conforms to the microcomponent height. Therefore, microcomponents with very low height require very thin magazines, which are not stable enough for mounting and transportation of the microcomponents. Additionally, it does not allow the packaging of complex microcomponent designs with undercuts, and microcomponents with tapered ends only can be pushed out of the magazine at the side opposite of the tapered end. A magazine designed as a positively enclosing plate generally is inconvenient for machine mounting of the microcomponents, e.g. using a gripper, since the gripper cannot grab the microcomponents at their sides.